Denmark & San Diego

HOERSHOLM, Denmark & SAN DIEGO, November 5, 2011 - - New Phase 2a clinical data to be presented in late-breaking oral presentation at AASLD - - Miravirsen given as a four-week monotherapy treatment provided robust, dose-dependent antiviral activity with a mean reduction of 2 to 3 logs from baseline in Hepatitis C Virus (HCV) RNA (log10 IU/mL) that was maintained for more than four weeks beyond the end of therapy - Four out of nine patients treated at the highest dose with miravirsen became HCV RNA undetectable during the study, providing clinicalevidence thatmiravirsen'sunique mechanism-of-action offers high barrier to viral resistance and the potential for treatment cures with monotherapy - Miravirsen, the first microRNA-targeted drug to enter clinical trials, works by inhibiting miR-122, a microRNA required for HCV accumulation, was well tolerated in patients with chronic HCV infection - Miravirsen's long-lasting suppression of HCV RNA, high barrier to viral resistance, low propensity for drug interactions and favorable tolerability profile holdspromise as pivotal new treatment option given as monotherapy or in combination with direct acting antiviral agents as an interferon-free treatment to eradicate chronic HCV infection in multiple genotypes Santaris Pharma A/S, a clinical-stage biopharmaceutical company focused on the discovery and development of RNA-targeted therapies, presents new data from the Phase 2a trial showing that miravirsen given as a four-week monotherapy treatment provided robust dose-dependent anti-viral activity with a mean reduction of 2 to 3 logs from baseline in HCV RNA (log10 IU/mL) that was maintained for more than four weeks beyond the end of therapy.